RU2613008C2 - Device and method for operating line oil heater - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: device comprises housing containing a hermetically sealed cavity. First tubular heat exchanger is disposed at the bottom of cavity for flue gas passing, its inlet and outlet fittings are located on the housing. Second tubular heat exchanger is disposed in the cavity for oil heating, with its nozzles connected to input and output pipes attached to the housing. Heat carrier is disposed at the cavity bottom.

EFFECT: simplified design, reduced consumption of materials, simplified manufacturing technology and use.

7 cl, 1 dwg

Description

The invention relates to the field of oil preparation at oil fields and oil refineries for its further transportation or processing.

A device is known for heating liquids in furnaces of the BN-3000 type (see the book: A. Antipov, “Thermal Calculation of Technological Lines and Thermotechnical Equipment for Oil Field Processing Facilities.” - Kazan: Feng, 2002. — pp. 165-166). This heating unit is a battery of heat exchangers of the pipe-in-pipe type, where the products of fuel combustion serve as the heating medium, and various oil liquids are used as the heated medium. The heated product moves in the annulus, the fuel moves in the annulus, where it, when burned, radiates heat absorbed by the heat-exchange surfaces. The heating of the oil fluid is carried out by direct contact with the heat exchange surfaces.

The disadvantage of this method is that coking of the heated oil occurs on the surface of the flame tube, which leads to a deterioration in the heat exchange between the combustion products of the fuel gas and the heated liquid, which, in turn, leads to rapid burn-out of the flame tube and fire hazardous contact of the combustion products with oil.

Known (http://www.mbcd.ru/rus/production/class_12/product_12) is an oil heater with an intermediate carrier for heating oil, oil-water emulsion or other field liquids, including a tank filled with coolant, a pipe coil with a fuel gas flow regulator, fire tube.

The disadvantage is that when hydrogen sulfide-containing gas is burned, hydrogen sulfide is oxidized to sulfur dioxide gas SO ₂ and, in part, to sulfuric anhydride SO ₃ . Sulfuric anhydride in the presence of water vapor forms sulfuric acid H ₂ SO ₄ . Sulfuric acid has a high boiling point and, accordingly, a low saturated vapor pressure. The partial vapor pressure of sulfuric acid, which is established in flue gases during the combustion of hydrogen sulfide-containing gas, can exceed the saturation pressure above cold sections of heat-exchange surfaces, since the temperature of the intermediate heat-transfer agent does not exceed 100 ° C and 110 ° C for water and antifreeze solutions, respectively. As a result, at certain temperatures of the heat exchange surfaces, conditions are created for condensation of sulfuric acid on them. Sulfuric acid corrosion of the material of the heat exchange surface and burnout of the flame tube occur, leading to an emergency stop of the heater and costly repair, that is, to a decrease in reliability.

In addition, in field conditions there is an uneven and intermittent supply of fuel gas (associated petroleum gas), which complicates its ignition in the gas burner device of the heater.

The closest analogue of the developed technical solution can be recognized (http://ingastech.ru/putevoi-podogrevatel-pp-1-6.html) track heater series PP-1.6 / PP-4.

The heater is a cylindrical horizontal tank with flat bottoms, in the inner cavity of which two P-type fire chambers and two 4-way tubular coils are installed in the lower part; in the PP-4V model there are four 4-input coils providing reduced hydraulic resistance. The tank is filled with liquid coolant (diethylene glycol) through the expansion tank.

Furnace devices are equipped with burners:

gas in the PP-1.6 model; PP-4; PP-4V;

liquid fuel in the PP-1,6Zh model,

combined in the model PP-1,6-K.

Outside the vessel, fuel preparation and supply units for burner devices, a coolant level indicator, a ladder, and a service platform are mounted. The heater is placed on the frame of the welded structure.

The heater operates as follows.

The product is fed into the coils, in which the product is heated from a coolant to 70 ° C. The temperature of the coolant is supported by automation + 95 ° C by controlling the power of the burners. The automation system of the heater PP-1,6 / -4 provides:

- regulation of fuel pressure in front of the burners;

- ignition of burners;

- maintaining the temperature of the product by automatically changing the burner mode from large to small combustion and vice versa;

- automatic shutdown of fuel supply to the burners with decoding and storing the root cause in case of:

- increase the pressure of gaseous fuel in front of the burners;

- lowering the fuel pressure in front of the burners;

- extinction of torch torches;

- increase the temperature of the coolant;

- increase the pressure in the food coil.

Automatic control system type SAPN PP is placed in a heated room, connecting to the heater with a wire line 150-200 m long.

A disadvantage of the known track heater should be recognized as significant material consumption, the complexity and duration of manufacture, the complexity of the design. In addition, diethylene glycol decomposes when heated, which necessitates its frequent replacement in the device.

The technical problem solved by the developed technical solution is to expand the range of means for heating oil and oil products during transportation, as well as their processing.

The technical result achieved by the implementation of the developed technical solution consists in simplifying the design, reducing its material consumption, as well as simplifying the manufacturing and use technology.

To achieve the specified technical result, it is proposed to use the developed device of the traveling oil heater. The developed device comprises a housing, preferably located horizontally, containing a hermetically sealed cavity, in the lower part of the cavity there is a first tubular heat exchanger intended for the passage of flue gases, the inlet and outlet fittings of which are located on the housing, in the cavity there is a second tubular heat exchanger for heating oil, connected to the oil inlet and outlet nozzles mounted on the housing, in the lower part of the cavity is a liquid chemically inert coolant.

The specified technical result is achieved due to the obvious simplification of the design, as well as the technology of its manufacture. The simplification of the technology of using the device is quite obvious - passing oil through the first tubular heat exchanger and through the second tubular flue gas heat exchanger.

To enhance the vaporization efficiency of the liquid heat carrier, it is preferable that the tubular flue gas heat exchanger be immersed in the liquid heat carrier — the lower monohydric alcohol, ketone or their aqueous mixtures.

To reduce heat loss, the surface of the body is covered with a layer of thermal insulation.

Typically, flue gas burners are located on the outside of the housing.

At least one temperature meter (in particular, a thermocouple or any semiconductor temperature meter) can be located in the first tubular heat exchanger in order to regulate the supply of thermal energy with the most effective effect on oil in the cavity, which registers the temperature of the vapor of the heat transfer medium. In addition, it is desirable to install a flue gas flow controller on the flue gas path. This will optimize the operation of the device and receive at the outlet of the first tubular heat exchanger oil with specified viscosity characteristics.

Also, to achieve the specified technical result, it is proposed to use the developed method of operation of the traveling oil heater. According to the developed method, the heating of oil passing through the first tubular heat exchanger located in a hermetically sealed cavity is carried out by condensation on the outer surface of the heat exchanger of the vaporous heat carrier, the liquid phase of which is located in the lower part of the cavity, and the heating of the liquid heat carrier is carried out by applying thermal energy to the liquid phase from flue gases passing through a second tubular heat exchanger.

The liquid heat carrier is preferably water-organic mixtures containing lower monohydric alcohols (methanol, ethanol, isopropanol) or ketones (acetone, methyl ethyl ketone). However, it is possible to use monohydric alcohols or ketones without mixing them with water.

Mostly the heating of the liquid coolant is regulated by the supply of flue gases - a change in the temperature of the flue gases or the feed rate.

The drawing shows the basic view of the developed device, with the following notation: case 1, cavity 2, first tubular heat exchanger 3, flue gas supply fitting 4, flue gas outlet fitting 5, second tubular heat exchanger 6, oil input fitting 7, output fitting 8 oil, liquid coolant 9, thermal insulation 10 of the housing 1.

The device operates as follows.

A liquid coolant 9 is poured into the cavity 2 of the housing 1 and the cavity 2 is tightly closed. Through the nozzle 4, the flue gases leaving the nozzle 5 are fed into the heat exchanger 3. The oil exiting the heat exchanger 6 is supplied from the heat exchanger 6 through the nozzle 8. Thermal energy of the flue gases is transferred to the liquid coolant 9, which begins to evaporate. The coolant vapors enter the upper part of the cavity, touch the cold surface of the heat exchanger 3 and condense on the indicated surface, transferring thermal energy to the metal of the heat exchanger and, therefore, oil. Condensed coolant drops under the influence of gravity fall down. Heated oil exits through port 8.

The developed technical solution is illustrated by the following implementation example.

A 50% methanol aqueous solution was used as the heat transfer fluid. The incoming flue gases have the following characteristics: temperature 400 ° C, process pressure (g) 0.3 MPa. Exhaust flue gases have the following characteristics: temperature 180 ° C, process pressure (g) 0.3 MPa. The incoming oil has the following characteristics: temperature + 58 ° C, process pressure 0.35 MPa. Outgoing oil has the following characteristics: temperature + 75 ° C, process pressure 0.35 MPa.

The given example confirms the effectiveness of the developed technical solution.

Claims (7)

1. The device of the path oil heater, characterized in that it contains a housing containing a hermetically sealed cavity, in the lower part of the cavity there is a first tubular heat exchanger designed to pass flue gases, the inlet and outlet fittings of which are located on the housing, in the cavity there is a second tubular heat exchanger designed for heating oil, connected to oil inlet and outlet nozzles mounted on the housing, in the lower part of the cavity there is a liquid coolant in which high tubular heat exchanger. 2. The device according to p. 1, characterized in that the surface of the housing is covered with a layer of thermal insulation. 3. The device according to p. 1, characterized in that the housing is installed horizontally. 4. The method of operation of the traveling oil heater, characterized in that the heating of the oil passing through the second tubular heat exchanger located in a hermetically sealed cavity is carried out by condensation on the outer surface of the second heat exchanger of the vaporous heat carrier, the liquid phase of which is located in the lower part of the cavity, and the liquid the coolant is carried out by applying to the liquid phase thermal energy from flue gases passing through the first tubular heat exchanger installed in the same cavity and immersed in a heat transfer fluid. 5. The method according to p. 4, characterized in that as a liquid coolant use aqueous-organic mixtures containing lower monohydric alcohols or ketones. 6. The method according to p. 4, characterized in that the heating of the liquid coolant is regulated by the supply of flue gases. 7. The method according to p. 4, characterized in that the generation of flue gases is carried out by burners located on the outside of the housing.

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